Late onset left diaphragmatic hernia

Clinical History

A young female patient with no trauma history came to the radiology department with the suspicion of pleural effusion. Thoracic ultrasound was performed and no pleural fluid was detected. She denied further examinations. Twenty months later she came back with dyspepsia, abdominal distention and flatulence.

Imaging Findings

Chest radiograph (Fig. 1) detected an extensive area of high density in the region of left lower lobe with round bowel-shaped hypodensities inside. These findings raised the suspicion of left diaphragmatic hernia.A contrast-enhanced thoracoabdominal CT was performed (Fig. 2). It demonstrated a left diaphragmatic defect with intrathoracic herniation of small bowel, distal ileum, cecum, right and transverse colon. Left colon, stomach, spleen and left kidney were located inside abdominal cavity and retroperitoneum. Thoracic apex was occupied by a segment of colon. Volume rendering images demonstrate relationship between colon and left atelectatic lobe (Fig. 3).

Discussion

A diaphragmatic hernia is an abnormal opening in the diaphragm, allowing parts of the abdominal organs to herniate into the thoracic cavity. Congenital diaphragmatic hernia is caused by the improper fusion of the diaphragmatic structures during fetal development. It is seen in 1/2200 to 1/5000 live births, 80 to 90% of cases occurring on the left side.Abdominal viscerae inside the pleural cavity causes pulmonary hypoplasia and affects bronchial and pulmonary vasculature development that leads to pulmonary hypertension.These patients may present with cleft palate, neural tube defects, oesophageal atresia and cardiac defects. Furthermore, some genetic anomalies are associated with congenital diaphragmatic hernias, like trisomies 13, 18 and 21 and tetrasomy 12p (Pallister-Killian syndrome).Traumatic rupture of the diaphragm indicates a high energy impact and is associated with other severe injuries like head injury, pelvic fractures and splenic and renal injuries.In the present case, no traumatic history was reported. Moreover, no anatomical defects were detected, except for left pulmonary loss of volume. It could be hypothesised that a small diaphragmatic defect, with no or minimal repercussion on pulmonary haemodynamics, may have be present at birth. This defect may have grown during the following years with subsequent intrathoracic herniation of small bowel and colon that caused the digestive symptoms.Teaching points:a) Diagnosis of congenital diaphragmatic hernia may be missed at birth.b) Some genetic diseases are associated with congenital diaphragmatic hernias.c) Traumatic diaphragmatic defects indicate a high energy impact, so other associated injuries should be suspected.